Passenger and commercial vehicles include sophisticated vehicle powertrain systems. That is, the powertrain generally includes an engine, transmission, clutches, etc. that work together to propel the vehicle. Hybrid vehicles introduce even more complexity into the powertrain system. In particular, the powertrain system of a hybrid vehicle may include one or more electric motors.
Each of these components in the powertrain system has operating constraints. For example, the engine and transmission may each be configured to operate at a certain range of speeds, and those ranges of speeds may be different. Operating a powertrain component outside of its operating constraint may cause the component to operate below its ideal capacity or possibly cause the component to fail. This may lead to an unpleasant driving experience for a driver of the vehicle.